Metal dowel-pin.



Patented July' l, |900.

TYDEN.

METAL DUWEL PIN.

V (Application led Nov. 8, 1899.) `(No Model.)

@lava/ba( NITED A STATES PATENT Clarion.y

EMIL TYDEN, OF HASTINGS, MICHIGAN.

METAL DOWELi-PIN.

SPECIFICATION forming part of Letters lPatentpNo. 653,327, dated July10, 1900.

Application filed November 3, 1899. Serial No. 735,665. (No model.)

being had to the accompanying drav'vings,

forming a part thereof.

'1 he purpose of this invention is to provide an improved metal dowelpin or tenon adapted `for use in situations in which it is essentialthat the pin or part performing the function of a dowel or tenon shallbe permanently and centrally rooted in one of the two parts to beunited, so that when they are separated it shall invariably remain inthat part rather than in the other. One of the most familiar situationsin which this requirement occurs is the case of leaves or fillers forextensiontables, which are connected to each other and to the fixedmembers of the table-top by tenons or dowel-pins rooted in one part andentering sockets in the adjacent part.

In the drawings, Figure l is a section of a block or board having myimproved dowelpin inserted and protruding, the pin being shown in planview. Fig. 2 is a side elevation of the pin. v

My improved dowel-pin is designed to be driven into the board or blockin which it is to be permanently rooted, the block being first bored toform a hole whose diameter is slightly less than the diameter of thepilotpoint and round portion of the body of the pin. In the case ofsoftwood the hole will be perceptibly less in diameter than the roundpart of the pin; but in hard wood it will be only enough less to causethe pin to drive tightly into it. A represents a block into which thepin is to be thus driven, and a the bore therein to receive the pin. Thepin comprises the pilot end portion B, which is preferably cylindrical,a flattened intermediate portion B', formedby striking the round rod orwirevof which the pin is made betweendies to flatten it in'one directionand expand it in the direction at right angles to the pressure or strokeby which it is iiattened, and a third portion B?, which constitutes theremainder of the body of the pin from the fiattened portion tothe'endandcomprises the portion which will protrude from the block to enter thepart to which the block is to be connected.

The iiattening of the portion B is done in such line sharpened orcomparatively-acute lower v edges b b', which face downward or inwardwith respect to the block into which the pin is driven. Preferably theselower edge portions are slightly extended down, being produced byswaging the metal of the wire or rod o from the sides of the cylindricalpilotportion at the upper end thereof, adjacent to the flattenedportion,as seen at blo in Fig. 2. Atvthe upper end of the flattened portion B'the formation of the dies is such as to produce quite abruptupwardly-facing shoulders b2 b2, which are 'not acute or sharpened likethe edges b', but, on the contrary, are preferably `quite blunt, asillustrated; also, in distinction from the abrupt upwardly-facingshoulders b at the point of merger of the pilot end port-ion B in theflattened portion B', the lower end of the cylindrical body portion B2where it merges into the iiattened portion B is merged in the flattenedportion of the sides of the`latter, preferably by easy-slopingshouldersb3 b3. The pilot portion B of this pin is designed to beof sufficientlength so that, fitting at least snugly in the hole which will be boredfor it in the block, it will insure accuracy of direction to the pin asit is driven home, and it is this quality or function of the pin whichcauses me to name it the pilot portion. The purpose of the sharpenedlower edges of the Iins as the lower side portions of the flattenedportion B' may be termed, is to open the grain of the wood as the pin isdriven home, and that of the abrupt shoulder b at the upper endof thepilot portionandat the sides of the flattened portion is to resist thewithdrawal of the pin, which it will tend to do, because 'the wood,having been slightly crowded out of position by the'pilot, will re- IOOact back over the shoulders when the pilot has passed. The same purposepertains to the abrupt and blunt shoulders b2 b2 at the upper end ofboth sides of the flattened por-v tion B', and at these points theresistance afforded by the wood opposing the withdrawal of the pin willbe greater even than that which is afforded by the shoulder b, becausethe grain of the wood will have been spread the whole thickness of thewing or fin of the pin, no part of the'wood having been removed, and thereaction when the fin has passed will insure a very effectivereoecupation of the space from which the wood has been displaced abovethese abrupt shoulders. The bore made for the pin should be long enoughlto permit the .flattened portion forming the fins described to be sunkquite a distance back of the face or edge from which the body of the pinis to protrude.

As above indicated, I make this pin of wire or rod susceptible of beingswaged into the shape described and of retaining sufficient stiffnessafter being thus swaged to be driven home, as indicated, without dangerof either breaking or bending in the process. It will be observed,however, that the construction tends very effectively to prevent the pinfrom being bent while driven home, because in the first place the pilotportion encounters only a moderate amount of resistance while itis beingentered in the bore and driven up to the. uns, and the fins themselves,sharpened at their lower edges, obtain consider-- able lateral supportin the wood before very serious resistance is encountered from thelatter. When the pin is driven home, it will be noticed that it isreinforced or supported bythewood closing snugly around its cylindricalportion at both ends of the liattened portion, so. that the liability tobe bent at the attened portion is very little, and this is renderedstill less by the fact that the flattened portion is so firmly embeddedin and engaged by the wood at both edges. I have described the processof inserting this pin above as if it were to be driven into the woodwith the flattened portion and fins extending in the direction of thelength of the grain, so thatthe-fibers of the wood will be parted by theentrance of the fins; but it can be driven crosswise of the grain, thelower edges of the fins being designed to be sharp enough to cuttheirway across the grain, at least of soft wood, when the situation in whichit is used is such that any advantage may be obtained by inserting it inthat manner.

For convenience of identifying the different partsof the pin I treat theend which is first entered into the wood and toward which the acute endsof the pins point as the lower end, regarding the end toward whichtheabrupt shoulders face as the upper end, and in the claims it-will beunderstood, there fore, that the words lower and upper are merelyrelative terms,and indicate direction or position toward the insertedand the protruding ends, respectively.

1. A dowel-pin made of cylindrical metal rod or wire, having at theopposite ends cy= lindrical portions and between such cylindricalportions a portion which is flattened to a thickness less than thediameter of the cy; lindrical portion and widened so as to forni finsprotruding at both sides beyond such cya lindrical portions, the loweredges of such protruding fins being acute, and the upward'ly-facingshoulders of the lower eylinf drical portion, where the device isreduced in thickness to form the fiattened portion, bea ing abrupt.

2. A dowel-pin made of cylindrical metal rod or wire having at the endscylindrical por tions, and between such cylindrical portions a portionwhich is flattened to a thickness less than the diameter of thecylindrical portions, and widened to form fins which project at bothsides beyond such cylindrical portions, the edges of the lower endsvofthe protruding fins being acute and their upper ends constituting abruptshoulders.

3. A dowel-pin made of cylindrical metal rod or wire having at theopposite ends cy lindrical portions, and between such cylin dricalportions a portion which is iattened to a thickness less than thediameter of the cy'- lindrical portion and widened to form ns projectingat both sides beyond such cylindrical portions, the lower ends of suchprojecting fins being acute, their upper ends forming abrupt shoulders,the lower cylin-a drical portion presenting abrupt shoulders facingupward where the pin is reduced in thickness at the iiattened part.

4E. A dowel-,pin made of cylindrical rod or wire, having at the oppositeends cylindrical portions, and between such cylindrical por=` tions aportion which is flattened to a thickness less than the diameter of thecylindrical i portion and widened to form us whichV project at bothsides beyond such cylindrical portions, such fins extending down a shortdistance alongside the lower cylindrical portion and terminating acutelyat their lower ends and abruptly at their upper ends, said lowercylindrical portion being relatively considerably extended beyond theacute termiu` nais of the pinsy to constitute a pilot or steer'- ingportion for the dowel-pin.

5. A dowel-pin made of cylindrical metal y rod or wire havingcylindrical end portions,-

and intermediate such cylindrical portions a portion which is attened toa thickness less `j than the diameter of the cylindrical portions j andwidened to form hns which extendl at both sides beyond such cylindricalportions, the lower cylindrical portion being extended i suitably toadapt it to serve as a pilot or steers 'ing portion for the pin, andhaving abrupt,

IIO

upwardly-facing shoulders at opposite sides my hand, in the presence oftwo Witnesses, at where the thickness is reduced to forln the Chicago,Illinois, this 30th day of October, flattened portion, the uppercylindrical por- 1899.

tion having long, sloping,'downwardly-facing A EMIL TYDEN, 5 shouldersWhere said reduction in thickness Witnesses:

occurs. CEAS. S. BURTON,

In testimony whereof I have hereunto set ADNA H. BOWEN, Jr.

